CLASSIFICATION OF STRUCTUEAL STEELS. 393
much, more irregularity in modes of fracture than similar samples of open-hearth steel."
My own experience leads me to think that Bessemer steel requires more work for the attainment of a proper structure than open-hearth, metal, so that a thick bar is more apt to have a coarse crystalline fracture. This may be ascribed to improper heat treatment, but if open-hearth metal would not be injured under a similar exposure, then there is a difference between the metals, and, if this be acknowledged, then there is no necessity for argument.
Bessemer metal has been used for rails, and these are exposed to great stress and shock, but a large number of rails break in service, and it is probable that the number of broken rails would be reduced if they were made of open-hearth steel. The making of open-hearth rails is a commercial question, and involves immense sums of money. Nearly all rails in America are made by the Bessemer process, and each rail-making plant must be regarded as a unit. The converting department is one factor of this unit, its whole scheme of operation being designed for the one purpose of supplying the blooming mill with just the right quantity of ingots. It may be that at a given rail-making works there is no 'open-hearth furnace plant at all. In such a case if open-hearth rails are wanted they can be made only by some such changes as the following:
(1) Bring cold blooms from other works, and erect a plant of heating furnaces.
(2) Bring cold ingots from other works, with the same necessity for heating furnace equipment. In both cases the extra fuel consumption and waste in heating would be serious matters.
(3) The foregoing propositions are temporary and the only true solution is an open-hearth plant. This calls for a large amount of capital, and when the plant gets into operation the Bessemer plant •will become a scrap heap of no value whatever, for in order that it shall be of any value it must run, and in order that it may run, it would be necessary to build a complete plant of rolling mills to handle its product.
(4) Having written off the value of the Bessemer outfit as a dead loss, it is necessary to guarantee business to the open-hearth department in sufficient quantity to keep it in steady operation at a price in proportion to the increased cost. It is out of the question to operate the open-hearth plant on certain orders for open-hearth